DISEASES OF THE PERITONEUM. 



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I. Chronic diseases of the heart, lungs, kidneys, of the portal 

 system and mesenteric ganglions, which determine sometimes gen- 

 eral circulatory troubles (heart, lung, kidney), at other times local 

 circulatory troubles (liver, portal vein, mesenteric ganglions) ; it is 

 the venous blood and mainly the lymph which, hindered in their 

 course, determine the transudations (passive ascites) : 



1. Concerning heart disease, we must especially mention here: 

 valvular insufficiencies of long standing, chronic pericarditis, and 

 epicarditis with abundant serous exudation or adhesion of the two 

 pericardiac layers (cardiac symphysis) ; hydro-pericarditis. 



2. Among the lung diseases we have emphysema and the inter- 

 stitial processes with sclerosis and consecutive atrophy (tuber- 

 culosis). 



3. In kidney diseases we may mention interstitial nephritis 

 (Bright's disease) and the degenerative processes. 



4. The liver troubles are : interstitial hepatitis leading to cir- 

 rhosis (in distomiasis and echinococcosis) and the neoplasms (ade- 

 nomas, carcinomas, etc.). 



5. Concerning affections of the portal system : compression of 

 the portal vein by tumors and thrombi. 



6. We have among the alterations of the lymphatic ganglions : 

 caseous degeneration and atrophy (infectious enteritis of the young 

 horse). 



In all these cases, if the discharge of the blood in the capillaries 

 and the veins is obstructed, or if any kind of an obstacle is opposed 

 to the circulation of the lymph, there is at first a stage with increase 

 of the intra-vascular pressure, to which is soon added a greater 

 permeability of the vascular walls due to a modification of the 

 endothelium. These conditions suffice to explain the passage of 

 the blood through the vascular walls. When the object which ob- 

 structs the circulation resides in the portal system, the capillaries 

 and veins of the peritoneum, as well as the roots of the portal vein, 

 are particularly congested. 



II. Hydremia — that is to say, the predominance of serum in the 

 blood — and mainly of albumin (hydremic or cachectic ascites). 

 Hydremia is idiopathic or symptomatic; it may be developed with- 

 out any morbid change, or may appear consecutively to chronic 

 affections and to exhausting diseases (watery and verminous cachexia 

 in the sheep and the ox). The transudation is here the effect of 

 an alteration of the vascular walls : ascites never exists alone ; with 



